Online retailer Amazon is to buy natural and organic food retailer Whole Foods Market as part of a US$13.7bn agreement which will see the two organisations merge, the companies have revealed.

The definitive merger agreement will see Amazon acquire the retail business in an all-cash transaction valued at US$42 per share, a figure which apparently includes Whole Foods Market’s current net debt.

“Millions of people love Whole Foods Market because they offer the best natural and organic foods, and they make it fun to eat healthy,” said Jeff Bezos, Amazon founder and chief executive. “Whole Foods Market has been satisfying, delighting and nourishing customers for nearly four decades – they’re doing an amazing job and we want that to continue.”

“This partnership presents an opportunity to maximize value for Whole Foods Market’s shareholders, while at the same time extending our mission and bringing the highest quality, experience, convenience and innovation to our customers,” said John Mackey, Whole Foods Market co-founder and chief executive.

Whole Foods Market will continue to operate stores under the Whole Foods Market brand and source from trusted vendors and partners around the world, Amazon said in a statement.

John Mackey will remain as chief executive of Whole Foods Market and Whole Foods Market’s headquarters will stay in Austin, Texas, it added.

Completion of the transaction is subject to approval by Whole Foods Market's shareholders, regulatory approvals and other customary closing conditions. The parties expect to close the transaction during the second half of 2017.